Image projection device



May 23, 1939. B. J. KLEERUP 2,159,616

IMAGE PROJECTION DEVICE Filed April 26, 1937 I 2 Sheets-Sheet 1 21? 1/ 31 '1 x 15 I l" I B. J. KLEERUP' 2,159,616

IMAGE PROJECTION DEVICE Filed April 26, 1937 2 Sheets-Sheet 2 I r I I 1 Patented May 23, 1939 UNITED STATES PATENT OFFICE ilton Manufacturing Company,

Two Rivers,

Wis., a corporation of Wisconsin Application April 26, .1937, Serial No. 138,882

1 Claim.

This invention relates to an image projection device more particularly for projecting strip film for scientific or educational purposes.

The invention is of particular utility embodied, as here shown, in a portable cabinet, for use by dentists to display to heir patients enlargements of film pictures illustrating, for example, the proper care of the teeth. The image projection method and means broadly disclosed herein is 10 covered in a pending application filed April 10,

1937, Ser. No. 136,088, by Howell G. Evans and the present applicant jointly. The present application discloses a device which is peculiarly adapted to be used in conjunction with the pro- 15 jector of said joint application.

Among other objects, the present invention provides, in combination with a horizontal surface having an aperture therein and a projector having operative parts mounted above and below 20 said surface in register with said aperture, reel means for moving a strip fihn across the aperture for projection purposes, the surface itself providing a support for the reel means, the latter being readily separable therefrom so as to permit the display of other types of films when so desired.

Other objects and advantages will be apparent from the following description, taken together with the accompanying drawings, in which:-v 30 Figure 1 is a general view showing the present invention associated with the preferred cabinet; Figure 2 is an enlarged plan view of a portion of the cabinet upper surface with the reel means associated therewith, parts being shown in sec- 35 tion and the projector lantern being omitted;

Figure 3 is a partially sectional view, taken on the line 33 of Fig. 2 with the projector lantern in position, parts being shown in elevation; 40 Figure 4 is a crosssection taken on the line 4-4 of Fig. 3;

Figure 5- is a similar cross-section taken on the line 55 of Fig. 3; and

Figure 6 is another cross-section'taken on the 45 line 6-6 of Fig. 2.

Referring in detail to the illustrative construction shown in the drawings, the cabinet to, pref erably of ornamental design, isof such a height that its upper surface I l is a convenient working 50 surface for a person of average height when standing, the cabinet being otherwise in proportion so that it may be readily moved by the dentist, with the aid of castors I2, from a position against a wall, to a position in front of 55 the patient seated in the usual dental operating chair. Since only the upper part of the cabinet need be utilized for the present invention, the lower part thereof may contain the usual drawers l3, for the convenience of the dentist, some of which may contain the films or other pictures to 5 be displayed.

The cabinet I0 is preferably specifically constructed in accordance with the disclosures of said pending joint application, reference to which may be had for details thereof. For purposes 10 of the present invention, it will suflice to say that the cabinet, adjacent its upper front, has a pair of swinging doors I4 which may be opened to discover the interior l5 of the cabinet in which is mounted a frame l6 carrying a translucent screen l1, through the rear side of which, by a system of mirrors (not here shown), a beam of light carrying the enlarged image is projected.

The projector lantern I8 is carried by the cabinet. II) to move toward and away from the surface II, for which purpose it may be suitably hinged thereto adjacent the upwardly continued rear wall IQ of the cabinet, an opening 20 in said wall permitting movement of the projector lantern as just described. Stops 2| on the back of the lantern l8, by contacting with the rear surface of the wall l9, limit forward rotative movement of the lantern.

The surface H and upper wall of the cabinet has an aperture 22 therein, in register with which, when rotated to operative position shown in Figs. 1 and 3, the projector lantern is disposed,

as well as the objective lens barrel 23 of the projector, the latter being carried by the upper wall 24 of the cabinet'directly below the aperture 22. The housing 25 of the projector lantern contains at its lower end a condenser lens 26 secured therein in the usual manner, for example, as by a, frame 21 and lug 28. Depending resiliently from the frame 21 is another frame 29 which carries a glass plate 30. As here shown, headed studs 3| pass through the frame 21 and are attached to the depending frame 29, the studs 3| being free to move in the frame 21 and being normally pressed downwardly as limited by their heads by light compression coil springs 32 to urge the glass plate 30 toward or into the aperture 22. Through the projector parts just described, including the aperture 22, is thus projected alight beam represented by the broken line 33, all as more fully described in said copending joint application.

In accordance with the present invention, supported on the surface H, and, when in position thereon, forming an operative part thereof, is

the reel means comprising a carriage 34 for the strip film to be displayed, the carriage with the film thereon being selectively separable from I the surface H and other projector parts. For

this purpose, revolubly mounted on upstanding portions 35 and 36 at each end respectively of the carriage 34 are spool supports 31 and 38. As

here shown, these spool supports are keyed to shafts 39 and 40 respectively which turn in bushings 4| and 42 threadedly received in the upstanding portions 36. Knurled knobs 43 and 44, rigid with the shafts 39 and 40 respectively per- ,mit manual rotation of the spool supports. It

will be understood that the spool supports are thus mounted at one end only in cantilever arrangement on said upstanding portions.

The cross-pin 45 keys the spool support 31v the mm strip in a corresponding groove in the spool, where it is frictionally retained, as is well known in the art.

I Having selected the desired film to be displayed, *such'asjthe film 41, the dentist slips the spool 46 carrying this film onto'its spool support 31 which is at one end of the carriage 34, and preferably at the lefthand of a person facing the cabinet. The spool 46 is caused to rotate with its tudinally. openings t 5| therein, communicatin with thegbore. ;A;jset' screw]52' carried" by'the.

desirably with the aid of guide rollers 53 and 54,

shaft 39 {which terminates short, of thejend spool support 31, in this. instance by a spring detent 49. This. maybe in the form of .-a wire. loop which has both ends"anchoredjas, jat 56 axially'ofth'e spool support 31 iiithe borei'forth the bore);and'at1one end of a radialiyfaiid ion iigagementith the b'oreof, the spool 46, thus normally'i c ng -the spool ,toturn with the The free endofthe strip-film 41 is then led,

along the film track provided by the plate portion 55 of the carriage 34, crossing the aperture 22, while the carriage is in position thereover as presently described, the film. being thereafter temporarily reeled upon another spool 56 which may be permanently secured; to its spool support as by a screw 61 passing through the spool support 38 and into engagement with the shaft 40.

Thefree end 58 of the film is temporarily inserted in a suitable groove in the spool 56. which, when the spool hasmade onerevolution with the film thereabout," prevents slippage oi the; film with respect to the spool. x Centrally of the-carriage 55 thereofis desirably ofiset downwardly as; at

to of the aperture} a U portion 59 of thecarriageh 6i therein which is p thelslot *5] to have resilient friction plateportion entral. cut-out slaggplatelha chamfered edge of the glass plate 62 at each end of the cut-out 6| engaging an inclined undercut margin of the cut-out 6|. Thereafter, to retain the plate 62 in position, a mask 63 having the central cut-out 64 is secured as by screws 65 to the bottom face ofthe offset portion 59 and within a longitudinally extending recess 66 therein.

The downwardly offset portion 59 of the carriage may fit somewhat snugly into a portion of the countersink 60 made to receive it as best shown" in Figs. 3 and 6.

Also downwardly depending pins 61 at each end of the carriage, received in suitably registering holes 68 in the surface H, may assist in locating the carriage in position as described. It will be understood that the projector lantern may be temporarily swung backwardly upon its pivot, when the reel carriage is placed in 'or removed from'position, and the lantern then moved back to operative position as shown.

When the projector lantern I8 is in operative position as shown, and the film'41 is threaded about the spools and guide rollers as just deface II, the lens system 23 being arranged for I proper projection of a film in this plane, as will be readily understood by those skilled in the art.

So constructed and arranged, the dentist or other operator may reel the film through the device, first from the spool 46 which is permanent 1th the film, onto the spool 56 which is permaefit with the carriage, the film passing progresveiy, rapidly or slowly as the dentist may desire, controlled by manual rotation of the knob 44,

through the, projector. The usuallight source being energized, the pictures on the strip film 4 1 are successively displayed on the screen i1. .Abeveled edge'69 on the. upper glass plate 30 prevents scraping of the'film by this plate and rovides somewhatin the nature of a cam action hichcauses the upper glass plate 30 to resiliently adapt itself to-the thickness of the film while still pressing the film against the lower glass plate to maintain the proper distance from the objective lens.

When all of the pictures on the strip have been displayed, the dentist, by manipulating the knob 43, may re-reel the film back onto the spool 46 and remove this spool with the film thereon for storage or for replacement by another spool with a difierent film thereon.

It will be understood that the invention is not limited to details of construction here described for. purposes of exemplification. Such changes maybe made as fall within the scope of the following claim without departing from the invention.

Having described my invention, I claim:

In an image projection device for use with a' "horizontal fiat workingsurface anda projection, lantern mountedto swing into and out of register over an aperture'in the surface, the combination fwith -a downwardly-spring pressed glass plate carried by the lanternioe-registerwith said aper- Q ,ture; of aunitary -filmj. arriage separable from the cabinet and lantern, said carriage compriscarrying said spool supports upstanding thereon,

said frame having a flat plateportion extending horizontally beneath the reels and including a central portion between the reels which is downwardly oitsetout of the main plane of the frame, the lower face of said downwardly offset portion providing registering means receivable in said aperture for registering the carriage thereover and the upper surface thereof providing a track for the fllm in substantially the plane of the said working surface when the film is pressed against said upper face of the downwardly oflset portion b" the said glass plate carried by the projector lantern, said downwardly oflsetfportion being out out centrally to provide a frame for and carrying another glass plate flush with said ofl'set 

